1. Field of Invention
The present invention relates to an optical component comprising a plurality of optical fibers arranged, and a production method thereof.
2. Related Background Art
As an optical component for transmitting an optical image, an optical component formed by arranging a plurality of optical fibers is widely known. The optical component comprises an incident surface and an output surface with the core and the clad of each optical fiber exposed so as to allow transmission of the optical image incident on the incident surface to the output surface.
Moreover, since the optical component has various advantages, such as a high transmission efficiency, and capability of achieving a small size of an optical system compared with a lens, it is utilized in various fields represented by a fingerprint detecting device.
Production of the optical component is executed, in general, by arranging and tying up a plurality of optical fibers having a round or square cross-section in a bundle for integral shaping. Therefore, according to the pressure in the integral shaping, the cross-section of the core of the optical fibers comprising the optical component becomes a polygon having subtenses parallel with each other, such as a square, and a hexagon so that the below-mentioned problem is generated.
That is, a light incident on the incident surface with a specific incident angle repeats reflection on the opposite surfaces parallel with each other so as to be outputted from the output surface with a specific output angle. As a result, a pattern having an intensity only in the specific output angle is formed in the output image outputted from the output surface so that the pattern becomes a noise so as to deteriorate the resolution of the optical component.
Accordingly, in order to solve the problem, an object of the present invention is to provide an optical component having a high resolution by preventing generation of the pattern noise and production method of the optical component.
In order to solve the above-mentioned problem, an optical component according to the present invention comprises a plurality of arranged optical fibers including a core and a clad formed around the core, characterized in that the core of each optical fiber having a substantially square cross-sectional shape, is divided into a plurality of areas via a partition part made from a material with a refractive index smaller than that of the core, and at least one of the optical fibers arranged adjacent with each other has the dividing direction of the divided core different from that of the other optical fibers.
Since the core of each optical fiber is divided into a plurality of areas via a partition part made from a material having a refractive index smaller than that of the core, a light incident on the core of each optical fiber with a specific incident angle proceeds in the core while repeating reflection not only by the surrounding clad but also by the partition part. Moreover, since at least one of the optical fibers arranged adjacent with each other has the dividing direction of the divided core different from that of the other optical fibers, even though the cross-sectional shape of the core is a substantial square having subtenses parallel with each other, formation of a pattern having an intensity only at a specific incident angle by repeating reflection of a light proceeding in the cores in all the optical fibers comprising the optical component only in a specific direction can be prevented. As a result, a pattern noise can be prevented so that an output image with a high resolution can be obtained.
Furthermore, a production method of an optical component according to the present invention comprises an arrangement step of arranging a plurality of optical fibers including a core and a clad formed around the core, and a shaping step of integrally shaping the plurality of the optical fibers arranged in the arrangement step by a heating and pressuring treatment, characterized in that the core of each optical fiber is divided into a plurality of areas via a partition part made from a material with a refractive index smaller than that of the core, at least one of the optical fibers arranged adjacent with each other is arranged with the dividing direction of the divided core different from that of the other optical fibers in the arrangement step, and the viscosity of the core under the temperature of the heating and pressuring treatment is smaller than the viscosity of the clad in the shaping step. By the use of the production method, the optical component can be produced easily.
The present invention will be more fully understood from the detailed description given hereinafter and the accompanying drawings, which are given by way of illustration only and are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.